1. Field of the Invention
The present invention relates to a mechanism for switching pinch rollers of an autoreverse car audio device, more particularly to a mechanism for switching pinch rollers of an autoreverse car audio device for switching pinch rollers by a switching lever actuated relative with a mode changeover lever installed at an autoreverse car audio device and for safely fixing a selected pinch roller.
2. Description of the Prior Art
Audio devices recently developed are designed to accomplish various functions like an autoreverse, a section repetition, etc. In particular, the autoreverse function automatically reverses a tape traveling movement after the tape is finished forward traveling. The autoreverse type car audio device having the autoreverse function comprises a mechanism for switching the traveling direction to a reverse direction when the forward traveling of the tape is finished. Also, the device needs a pinch roller switching device in which one pinch roller is lifted from a corresponding capstan and the other pinch roller approaches the other capstan. Hence, various pinch roller switching devices are proposed.
One of the conventional pinch roller switching devices is disclosed in U.S. Pat. No. 4,932,605. In FIG. 1, the conventional pinch roller switching device comprises a pivotal drive mechanism 9 which is rotatable between two turntables to drive a first turntable in a first position and a second turntable in a second position. The pivotal drive mechanism 9, when it is pivoted between its first position and its second position in the case of reversing the direction of tape transport, actuates a change-over device for a pair of pressure rollers. The change-over device by means of slides 49, 50 lifts a first pressure roller 32 or a second pressure roller 33 journalled on levers 34, 35 off an associated capstans 30, 31 against a spring force. The pressure roller levers 34, 35 are pivoted about a pivotal axis 25 by the pivotal drive mechanism 9 and the slides 49, 50 via a first and a second cam lever 24 respectively. The cam levers 24 comprise cam surfaces which are followed by the pressure roller levers 34, 35. When the pivotal drive mechanism 9 approaches the first turntable wheel 12 or the second turntable wheel 13, one of the cam levers 24 is pivoted further via a pressure position of the cam surface by the spring force acting on the associated pressure-roller levers 34, 35, in such a way that one of the slides 49, 50 is urged into an end position by the pressure-roller levers 34, 35. In the end position the pivotal drive mechanism 9 is disengaged from the change-over device.
The conventional pinch roller switching mechanism of the autoreverse car audio device as described above is complicated because of the switching the pinch rollers by using levers, arms, and handspikes.